An image reading apparatus that reads a reading surface of a document includes, for example, a platen, a copyholder, and a reading unit. The copyholder includes a transparent flat plate and presses a document by the transparent flat plate to hold the document so that the document placed on the platen does not move. The reading unit uses light penetrating the transparent flat plate from the reading surface of the document that is pressed by the transparent flat plate, to read the reading surface (see, for example, Japanese Laid-open Patent Publication No. 63-31268).
A service for computerizing various documents has been widely developed. For example, even in the image reading apparatus described above, albums, long accordion documents, and large documents exemplified by a handscroll may move or fall off due to the weight of a portion protruding from the platen. Thus, the image reading apparatus cannot hold the document appropriately.